Fluid motor



June 25, 1946. c. SENN 2,402,848

' FLUID MOTOR Fil'ed May 25, 1945 2 Sheets-Sheet 1 fia 2' 8 a LL R,

I I a INVENTOR.

CHARLES same ATTORNEY C. SENN FLUID MOTOR June 25,, 1946 Filed May 25, 1945 Z'Sheets-Sheet 2 FIG.5, H

'INVENTOR, v CHARLES seam X "'TORNEY Patented June 25," 1946 UNITED STATES PATENT OFFICE FLUnJ oToR Charles sens, Detroit, Mich. Application May 25, 1945, Serial No. 595,735

plication, Serial Number 535,319, filed May 12,

Objects of the invention are to provide improved means for delivering a pressure fluid to and from the pressure chambers of a fluid motor; to provide for adjustment of a packing nut dis-' posed interiorly and at the axis of such a motor without disassembly of the motor; and to provide in a novel manner for air cushioning the retractive stroke of the reciprocating member of the motor.

These and various other objects are attained by the construction hereinafter described and illustrated in the accompanying drawings, wherein:

Fig. 1 is an axial sectional view of the improved motor, showing the initial position of the working stroke.

Fig. 2 is a view in side elevation showing the final position of said stroke.

Fig. 3 is a front end view of the motor.

Fig. 4 is a cross sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is a cross section taken on the line 55 of Fig. 1.

In these views, the reference character I designates an outer or guide cylinder formed with a suitable base 2, whereby the cylinder may be bolted down on any desired support. Said cylinder is integrally formed at its rear end with a head 3 and its front end is open. Slidably guided in the described cylinder is a cylinder 4 of a length adapting it to substantially fully occupy the bore of the guide cylinder The cylinder 4 extends through the open front end of the cylinder l and has its own front end closed by a head 5 secured to such end by cap screws 6, the arrangement being such that the head 5 is closely adjacent to the open front end of the cylinder I when the inner cylinder is fully retracted, as in Fig. 1. Preferably the head 5 has a central boss I inserted in and closely fitting the cylinder 4, and a packing ring 8 is compressed between said boss and the forward edge of the cylinder 4.

Fixed within and slidably engaging the front end portion of the cylinder 4 is a piston 9 rigidly carried by the front end of a rod l0 having its rear portion centrally mounted in the head 3 and clamped to the latter by a nut ll. Said rod projects rearwardly of the head 3 for reasons which will presently appear. The rear portion of the inner cylinder is slidably fitted on the rod 1 Claim. CI. 121-438) I0 and is chamber-ed to receive annular packing I2 sealed against the rod under compression of a nut 13. This packing will occasionally require tightening and a provision is made for turning the nutl3 for that purpose without disassembly of the motor. Thus the rear portion of the nut l3 has a series of circumferentially spaced, radial openings l4 outwardly of which the cylinder 4 is formed with a slot I5. Inthe fully retracted position of thecylinder '4, this slot l5 registers with a slot IS in the cylinder I normally covered by an arcuate plate IT. This plate is readily removable by unfastening screws l8 and thereupon a suitable pin (not shown) may be inserted through the slots l5 and I6 to enter any of the openings l4 and thus turn the nut. Circumferential extent of said slots is adequate to afiord swinging of the inserted pin through a substantial are, as is evident from Fig. 5.

Between the head 5 and piston 9 there is formed a high pressure fluid chamber l9 wherein fluid is accumulated to force the cylinder 4 forward on its working or power stroke. A pipe 20 extends within the rod in from end to end thereof to 5 deliver fluid to and discharge it from the chamber I9. Between the rear face of the piston and an interior annular shoulder 2| on the cylinder 4 there is formed a low pressure fluid chamber 22 wherein fluid is accumulated to retract said cylinder, the rod having a bore 23 extending from its rear end substantially to the piston to deliver fluid to and discharge it from the chamber 22. A port 24 laterally opens from said bore into the chamber 22 closely adjacent to the piston and a port 25 laterally opens from the projecting rear portion of the rod into a fitting 26 from which a hose 21 leads to a fluid source (not shown). As best appears in Figs. 4 and 5 the pipe 20 is of lesser diameter than the bore 23 anddisposed eccentrically in the latter, being preferably tangent to the bore along a line opposed to the ports 24 and 25. Said pipe projects sufilciently-rearward of the rod in for connection to a hose 28 or the like leading to any fluid source (not shown). An insert 29 fits exteriorly on said pipe and is welded or otherwise fixed in the rear end of the bore to close such end,

To positively restrain the cylinder 4 from any rotation, a key-way 30 is longitudinally extended in the outer face of such cylinder to receive a key 3| exteriorly mounted on the cylinder l and projecting through a slot 32 in the latter. Any

suitable valve mechanism may control the fiow through the hoses 21 and 28 to initiate the proability of this fluid motor are highly desirable, rendering it feasible to readily shift same to and install it in any location where it may be needed. It is important to appreciate that this motor is designed for precision work, asdistinguished.

tially coextensive and one operating within the 7 other.

" 'What I claim is:

A fluid motor comprising a fixed cylinder having a headed-rearend and an open front end, a pistonrod fixed upon and forwardly extending: M

4 from said headed rear end, a cylinder reciprocably fitted in and guided by the fixed cylinder and extending through said open end and having a headed front end and a rear portion in fluid sealing engagement with said rod, a piston fixed on the forward portion of said rod within the reciprocable cylinder and forming a front and a rear expansible fluid chamber respectively with the frontend and rear portion of the reciprocable cylinder, said rod being formed eccentrically with a passage extending from the rear end portion of the rod approximately to the piston and having a fluid delivery connection to said passage rearwardly of the fixed cylinder and a fluid connection to the rear expansible chamber from the front portion of said passage, said fluid connections being in the relatively thick portion of the wall of said passage, and a pipe of lesser diameter than said passage extending in said passage from the rear portion of said rod to and substantially through the piston for fluid delivery to and from the front expansible chamber, said pipe being substantially against the wall of said passage opposed to said fluid con nections, whereby the spacing of said pipe from the passage wall is a maximum at said fluid connections.

CHARLES SENN. 

